Consulta: subjectFacets:"Dating"
Registros recuperados: 4
Data/hora: 13/06/2024 05:37:56

Retrospective study of metal contamination time trends in the French part of the Bay of Biscay
Provedor de dados: 5
Autores: Boutier, Bernard; Quintin, Jean-yves; Rozuel, Emmanuelle; Auger, Dominique; Bretaudeau-sanjuan, Jane.
Two cores were sampled in the Bay of Biscay: one a few miles off the Gironde estuary (pointe de la Coubre), the other near the Spanish border (Capbreton canyon) to study past variations in sediment contamination. Radiochronology (210Pb, 137Cs) and total metal determinations by ICP-MS allowed the study of time trends for metal concentrations in sediment. Off the Gironde, during the time interval recorded by the core (1958–1999), all metal concentrations remained less than OSPAR background values. Some variations occurred along the Cd and Zn profiles, which may correspond to a very attenuated signal from the Gironde outputs. This suggests that this area was not submitted to any significant anthropogenic input of metals between 1958 and 1999. In the canyon of...
Tipo: Text
Palavras-chave: Sediment; Metal contamination; Dating; Cores; Time trends.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00061/17254/16094.pdf

Dating stalagmite from Caverna do Diabo (Devil´S Cave) by TL and EPR techniques
Provedor de dados: 42
Autores: WATANABE,SHIGUEO; CANO,NILO F.; RAO,T.K. GUNDU; SILVA-CARRERA,BETZABEL N.; CARMO,LUCAS S.; QUINA,ANTONIO J.A.; GENNARI,ROSELI F.; MUNITA,CASIMIRO S.; AYALA-ARENAS,JORGE S.; FERNANDES,BRUNO G.
ABSTRACT A cylindrical fragment of stalagmite from Caverna do Diabo, State of São Paulo, Brazil, has been studied and dated by thermoluminescence and electron paramagnetic resonance techniques. The thermoluminescence glow curves of stalagmite samples and subsequently gamma irradiated, have shown rise of three peaks at 135, 180 and 265 °C. From electron paramagnetic resonance spectra of stalagmite was possible to clearly identify three paramagnetic centers in the g = 2.0 region: Centers I, II and III are due to , and , respectively. The additive method was applied to calculate the accumulated dose using thermoluminescence peak at 265 °C and the electron paramagnetic resonance signal at g = 1.9973 of CO- 2 radical. The ages of the different slices of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Stalagmite; Caverna do Diabo; Dating; TL; EPR.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000602137

Dating of fossil human teeth and shells from Toca do Enoque site at Serra das Confusões National Park, Brazil
Provedor de dados: 42
Autores: KINOSHITA,ANGELA; SULLASI,HENRY L.; ASFORA,VIVIANE K.; AZEVEDO,RENATA L.; GUZZO,PEDRO; GUIDON,NIEDE; FIGUEIREDO,ANA MARIA G.; KHOURY,HELEN; PESSIS,ANNE-MARIE; BAFFA,OSWALDO.
ABSTRACT This work reports the dating of a fossil human tooth and shell found at the archaeological site Toca do Enoque located in Serra das Confusões National Park (Piauí, Brazil). Many prehistoric paintings have been found at this site. An archaeological excavation unearthed three sepulchers with human skeletons and some shells. Two Brazilian laboratories, in Ribeirão Preto (USP) and Recife (UFPE), independently performed Electron Spin Resonance (ESR) measurements to date the tooth and the shell and obtain the equivalent dose received by each sample. The laboratories determined similar ages for the tooth and the shell (~4.8 kyBP). The results agreed with C-14 dating of the shell and other samples (charcoal) collected in the same sepulcher. Therefore,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dating; ESR; EPR; Shell; Tooth; Enamel.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000300847

TL, OSL and C-14 dating results of the sediments and bricks from mummified nuns' grave
Provedor de dados: 42
Autores: Tudela,Diego R.G.; Tatumi,Sonia H.; Yee,Márcio; Brito,Silvio L.M.; Morais,José L.; Morais,Daisy de; Piedade,Silvia C.; Munita,Casimiro S.P.; Hazenfratz,Roberto.
This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at "Luz" Monastery, located in the state of São Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dating; Thermoluminescence (TL); Optical stimulated Luminescence (OSL); Mummified Nuns; Mosteiro da "Luz".
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000200002